1. Field of the Invention
The present invention relates to an electrical connecting device and, more particularly, to a connector including a protrusion integrally formed on an electrically insulating body, the protrusion being deposited with an electrically conducting layer to constitute a contact element.
2. Description of the Related Art
In recent years, electronic equipment, as well as various types of electronic parts incorporated therein, have been required to be reduced in the dimensions and weight thereof. According to such requirements, for example, board connectors, used for electrically connecting a pair of circuit boards with each other, have been made with narrow pitches of the array of contact elements incorporated therein, in order to reduce the areas to be occupied on the circuit board or to increase the density of lines provided thereon.
In a conventional connector which includes contact elements stamped from a metal plate by a press machine and press-fitted into through holes formed in a resinous body, it is difficult to maintain the molding precision of the body, and to prevent the contact elements from short-circuiting, as the pitch of the contact elements array becomes narrow. Accordingly, a connector has been provided which includes a plurality of conductive portions for electric connection formed by plating predetermined surface portions of the resinous body (see, e.g., Japanese Unexamined Patent Publication (Kokai) No. 2-297880). This type of connector having plated conductive portions can facilitate the reduction of the weight of the connector and can simplify a high-density arrangement of the conductive portions on the body surface. However, simply forming the plated conductive portions on the body surface may make it difficult to ensure sufficient contact pressure required for the conducting contact points of the connector. That is, in this structure, the contact pressure is affected by the molding precision of the resinous body and, therefore, contact reliability may be deteriorated unless the body is precisely molded so as to permit male and female connectors to be constantly tightly fitted with each other without substantial looseness.
Japanese Unexamined Patent Publication (Kokai) No. 3-173080 discloses a connector including protrusions integrally formed on an electrically insulating body, the protrusions being deposited on the surfaces thereof with electrically conducting layers to constitute contact elements. In this connector, the protrusions are fixedly supported in a cantilever manner on the body and, thereby, a desired elasticity or spring action is imparted to the plated contact elements. According to this connector, it is possible to ensure sufficient contact pressure for the.conducting contact points of the contact elements, even when the body and the protrusions have dimensional tolerances.
In the above connector having the integrally-formed cantilever contact elements, a lack of mechanical strength of the protrusions forming the contact elements may result in a relatively easy breakage of the contact elements, when an external force is inadvertently applied on the distal ends of the contact elements or when the connector is roughly connected or disconnected with a mating counterpart connector. Therefore, it is required that the protrusions are formed with sufficient thicknesses to maintain a desired mechanical strength and, consequently, it becomes difficult to establish the high density arrangement of the contact elements.
It is, therefore an object of the present invention to provide a connector having a contact element formed integrally with a body and which can maintain a mechanical strength of the contact element against an external force and can permit the high density arrangement of the contact element.
Another object of the present invention is to provide a method, of producing a so-structured connector, which can enable low-cost and high-precision manufacturing of a high-density, light and small connector.
In order to accomplish the above objects, the present invention provides a connector comprising an electrically insulating body; and at least one contact element provided in the electrically insulating body, the contact element including a protrusion integrally formed on the electrically insulating body and an electrically conducting layer deposited on a surface of the protrusion; wherein the at least one contact element is fixedly supported at opposite ends thereof on the electrically insulating body to exert elasticity.
In this connector, the electrically insulating body may include a bottom wall and a mutually opposed pair of side walls extending uprightly from the bottom wall, and the at least one contact element may be a plurality of contact elements protruding from at least one of the opposed surfaces of the side walls.
The connector may further comprise a plurality of electrically conducting terminals formed on a surface of the bottom wall facing away from the opposed surfaces of the side walls, each of the electrically conducting terminals being individually connected to the electrically conducting layer of each of the contact elements.
In this arrangement, the side walls may be provided with openings located respectively adjacent to the contact elements, and the electrically conducting layer of each of the contact elements may be connected to a corresponding one of the electrically conducting terminals through a corresponding one of the openings.
Each of the openings may be defined at a projected region of each of the contact elements on at least one of the opposed surfaces of the side walls.
Also, each of the contact elements may extend in a convexly curved manner on at.least one of the opposed surfaces of the side walls.
Further, the plurality of contact elements may be respectively formed on the opposed surfaces of the side walls to constitute two contact-element arrays.
Also, the electrically conducting layer may be formed over an entire surface of the protrusion.
The present invention further provides a method, of producing a connector, comprising molding a primarily molded body including at least one protrusion; molding a secondarily molded body on the primarily molded body to form an electrically insulating body in which the at least one protrusion is integrally formed and fixedly supported at opposite ends thereof on the electrically insulating body, the secondarily molded body partially covering the primarily molded body except for a surface of the at least one protrusion; and depositing an electrically conducting layer on the surface of the at least one protrusion.
In this method, the depositing step may include subjecting the electrically insulating body and the at least one protrusion to a plating process.
This method may further comprise, before molding the secondarily molded body, pre-treating the primarily molded body to be adaptable to the plating process.
Also, the primarily molded body may be molded to include a bottom wall and a mutually opposed pair of side walls extending uprightly from the bottom wall, the at least one protrusion may be a plurality of protrusions protruding from at least one of the opposed surfaces of the side walls, and the secondarily molded body may be molded to cover at least a part of the bottom wall and the side walls.
This method may further comprise, simultaneously to the depositing step, depositing an electrically conducting layer on a surface of the bottom wall facing away from the opposed surfaces of the side walls to form a plurality of electrically conducting terminals, each of the electrically conducting terminals being individually connected to the electrically conducting layer formed on each of the protrusions.
Also, the primarily molded body may be molded to be provided with openings in the side walls, located respectively adjacent to the contact elements, and the electrically conducting layer formed on each of the protrusions may be connected to a corresponding one of the electrically conducting terminals through a corresponding one of the openings.